This invention relates to personal wireless communications devices, and more specifically to communications device designs that reduce the radiation received by the user.
The use of cellular phones and other wireless communication devices have become very popular in recent years. (PDA""s phones, cellular phone, walkie-talkies, digital communicators, wireless phones, and others are among the many ways we communicate. Along with these phones has come the fear that they may cause health problems, including cancer. Whether this fear is founded or just hysteria, science has yet to determined conclusively. However, the fact remains that the majority of people presently want devices that limit their exposure to electromagnetic radiation emitted by these communication devices. And the Environmental Protection Agency has taken the threat seriously enough to fund expensive long-term research in this area and has issued cautionary warnings about the extended use of cellular phones. The problem is particularly great with modern cellular phones and other high power wireless communication devices which use the new very short antennas. These short antennas produce a much higher power density around the antenna compared to older long antennas. When in use, these personal communication devices are brought to rest against the user""s ear and the antenna is positioned approximately one inch away from the user""s head with their brain absorbing a considerable portion of the antenna radiation. People""s biggest fear is that very this close proximity of a high-power antenna to the user""s skull can cause brain cancer and leukemia. Besides the possible problem with cancer, placing a person""s head so close to the antenna also causes a significant portion of the transmitted energy to be absorbed or blocked. This reduces the transmitted signal and can cause communication problems due to a weakened signal.
Inventors have attempted to solve the radiation absorption problem by designing a multitude of ways to block and shield the transmitted signal from the user""s head. Unfortunately, these designs still create very strong radiation patterns near the user""s head, and also interfere with transmission and reception of signals. Many companies have compromised by simply moving the location of the antenna a few millimeters further away from the user""s head. Angling the antenna slightly away from the user""s head is also a common practice.
However, prior art does exist which may reduce radiation exposure for the user, including:
Foreign Patent WO0193611 published Dec. 6, 2001 to Harris of Australia
U.S. Pat. No. 6,246,374 on Jun. 12, 2001 to Perrotta
U.S. Pat. No. 6,184,835 on Feb. 6, 2001 to Chen
U.S. Pat. No. 6,104,350 on Aug. 15, 2000 to Ng
U.S. Pat. No. 5,561,437 on Oct. 1, 1996 to Phillips
U.S. Pat. No. 5,508,709 on Apr. 16, 1996 to Krenz
U.S. Pat. No. 5,337,061 on Aug. 9, 1994 to Pye
U.S. Pat. No. 5,170,173 on Dec. 8, 1992 to Krenz
U.S. Pat. No. 5,014,346 on May 7, 1991 to Phillips
U.S. Pat. No. 4,571,595 on Feb. 18, 1986 to Phillips
None of the prior art appears to show the Applicants"" designs. The Applicants"" invention can provide radiation intensities to the user""s brain nearly an order of magnitude lower than any of the above prior art. The Applicants"" design may also provide better reception at the same power level than prior art because of reduced signal absorbed by the user""s head and face. The physical distance placed between the user and the transmitting antenna accomplishes this. Mounting the antenna on the bottom achieves this distance (see FIG. 3). Angling the antenna at the bottom of the phone can further increases the distance (see FIGS. 8 and 10), and combining a bottom mounted antenna with an angle-away body section (see FIGS. 4, 6, 7 and 12) can further reduce the radiation intensity absorbed by the user over the best prior art.
The disclosed invention solves the radiation problem for wireless communication devices by placing the transmitting antenna on the bottom of the communication device. Radiation levels can be further reduced by angling the transmitting antenna on the bottom of the communication device so that it angles away from the user""s face while in use. The phone housing may also be angled so that the bottom portion of the phone is positioned away from the user""s head and brain, which effectively positions the transmitting antenna significantly away from the user""s head and brain. The result is that the user absorbs less total energy, and the highest intensity electromagnetic radiation (xe2x80x9chot spotxe2x80x9d) next to the brain can be eliminated. This repositioning of the antenna places the antenna at about chin and neck level on the user depending on how they hold the phone. This has the secondary advantage that it allows more horizontally transmitted signal to escape absorption. Absorption is reduced both because of the thinner effective cross-section of the user""s chin and neck area, and the greater distance the antenna is away from the user""s chin and neck. Also, if a directional transmitting antenna can be used (see FIG. 7B) the user can absorb even less of the electromagnetic radiation. The result is a much smaller percentage of the transmitted and received electromagnetic radiation can be absorbed by the user, thus improving both transmission and reception of electromagnetic signals.
Accordingly, the disclosed invention can have one or more of the following objects and/or advantages:
a) To allow a cellular phone antenna to be moved significantly away from the user""s head and brain, thereby greatly reducing the potential damage done by electromagnetic waves.
b) To provide antenna transmission at approximately chin or neck level, to improve horizontal transmission field due to the thinner cross-section of the user""s chin area and neck (less absorption) compared to placing the antenna near the user""s head.
c) To provide a directional antenna in the bottom portion of a phone to further reduce radiation absorbed by the user""s head.
d) To use lower transmitter power settings because of the better horizontal transmission field mentioned in item xe2x80x9cb)xe2x80x9d and xe2x80x9cc)xe2x80x9d above.
e) To greatly reduce total radiation absorbed by a user""s brain and head when using a wireless communication device.
f) To greatly reduce the electromagnetic energy intensity (power density-watts/cm{circumflex over ( )}3) experienced by the user""s brain.
g) To locate the normal operating position for a wireless communication antenna a significant distance away from the user""s head without significantly changing the general ergonomics of the wireless device.
h) To greatly reduce radiation absorption from wireless communication devices, and reduce the need for radiation shields or remote earphones and microphones.
i) To allow the user to adjust the angle of the antenna for better reception while at the same time reducing the user""s exposure to high-intensity antenna radiation.
j) To allow the ear piece portion of the wireless device to be at an angle with respect to the majority of the device so that the body of the phone angles far away from the operator when used (FIGS. 7A and B). With the antenna on the bottom of the phone the radiation pattern can be placed further away from the user""s face than with phones which may be angled near their mid-section (FIGS. 4 and 6).
k) To allow lower radiation levels by mounting an antenna on the lower back portion of the wireless communication device (see FIGS. 7A, 7B and 8).
l) To allow standard antenna designs and transmitters to be used with the new invention without the need for major modifications, thereby reducing the cost of modifications to the phone.
m) To provide a bottom mounted antenna that is pivotal along one and/or two axis.
n) To allow much higher transmitter power levels while maintaining safe radiation levels to the user""s brain by operating the antenna a significant distance away from the user""s head.
o) To provide a flip-open phone where the antenna is in the lower portion of the phone and the phone opens to angle backward away from the user""s face when in use.
p) To provide a flip-phone design which opens to more than 180 degrees (see FIGS. 9, and 12A and B) and has the battery and speaker in the top portion of the phone.
q) To provide a flip-phone design which opens to more than 180 degrees and has the keypad and antenna in the bottom (lower) portion of the phone (see FIGS. 12AandB).
r) To provide a flip-phone that can be designed to be gripped by the upper portion of the phone so that the user""s hand and fingers are exposed to lower levels of electromagnetic radiation from the transmitting antenna on the lower portion.
s) To provide a flip-phone that can be designed to easily be gripped by the upper portion of the phone and not easily gripped by the lower portion of the phone to encourage the user to keep their hand and fingers away from the transmitting antenna on the lower portion. This both reduces absorbed radiation, and improves transmission and reception of electromagnetic signals.